Electric switch.



. e. B. GRAY.

ELECTRIC SWITCH.

APPLICATION FILED NOV. 1, Ian. RENEWED AUG. 16.1916.

1 ,2 1 7,440. Patented Feb. 27, 1917.

2 SHEETS-SHEET I.

J3 If I] Attorneys G. B. GRAY.

ELECTRIC SWITCH.

APPLICATION FILED NOV. 1. 1911. RENEWED AUG. 16.1916.

0 O fly Patented Feb. 27, 1917.

2 SHEETS-SHEET 2 I I Attorr neys UNITED STATES PATENT OFFICE GARDNER B.GRAY, OF PITTSBURGH, PENNSYLVANIA,

ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AUTOMATIC TRAIN CONTROL 8: SIGNALCOMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE.

ELECTRIC SWITCH.

Patented Feb. 27, 1917.

Original application filed August 30, 1909, Serial No. 515,259. Dividedand this application filed November 1, 1911, Serial 110 658954. RenewedAugust 16, 1916. Serial No. 115,333.

To all whom it may concern:

Be it known that I, GARDNER B. GRAY, a citizen of the United States,residing at Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Electric Switch, of whichthe following is a specification.

This invention has reference to improvements in electric switches, andis designed to provide an electric switch of general application, butwhich at the same time is particularly useful in connection with anautomatic safety signal system for railways for which a Patent No.909,083, was issued J anuary 5, 1909. This particular application is adivision of application SerialNo. 515,259 filed August 30, 1909.

The primary object of this invention, is the provision of an electricswitch having a circuit controller responsive to fluid under pressureand means for governing and regulating the action of said controller.

By the means hereinafter fully described, is provided an electric switchcapable of being controlled by fluid under pressure to move it from itsinitial position to close a circuit, the extent of the pressure foroperating the switch being controlled by a pressure actuated device, andupon release of said pressure the switch will return to its normal orinitial position and the fluid required for operating the switch will bereturned to its initial source by means of a by-pass around saidpressure actuated means.

With the foregoing and other objects in view which will appear asthedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being understood that changes in the preciseembodiment can be made within the scope of what is claimed, withoutdeparting from the spirit of the invention.

In the drawings Figure 1 is a lon 'tudinal section, with parts inelevation, 0 an electric switch embodying the present invention.

Fig. 2 is a section on line AB of Fig. 1.-

Fig. 3 is a section on line C-D of Fig. 1, the piston in the chamber 3being omitted in this view for the purpose of showing the valve cage 14.

Fig. 4 is an end elevation of the structure of Fig. 1 from the switchend, with parts omitted.

Fig. 5 is a section on line E-F of Fig. 4.

Fig. 6 is a section on line G-'H of Fig. 1, the Bourdon tube and themounting for the same being shown in elevation.

Referring to the drawings, the numeral 1 designates the body, havingformed at one end thereof, the pressure chamber 2 and piston chamber 3,which are closed at the top by the cap plate 4. The chamber 2 is enteredby a pipe 5 coming from any suitable source of compressed fluid, suchfor instance as from the pressure side of an air-brake system on atrain. Mounted in the chamber 3 is a piston 6, normally held toward thebottom of the chamber 3 by a spring 7. This spring 7 engages at one endthe piston 0 and at the other end is engaged by the block 8 which may beadjusted by a set screw 9, passing through a threaded opening in the capplated. the nut 10 looking said screw at the desired adjustment.

The supply conduit 11 forms a communicating means between the twochambers 2 and 3, the valve 12, provided with the passage 13, being hereshown as controlling the conduit at the bottom of chamber 3. Themovement of the leak valve 12 from its seat is limited by means of thecage 14, which may be screwed to a nipple 15 formed on the end wall ofthe chamber 3 where the valve is located.

Leading from the chamber 3 is a conduit 16 which extends to a smallvalve chamber 17, opposite the end of the body occupied by chambers 2and 3. Access to chamber 17 is had through an opening normally closed bythe screw plug 18. The valve chamber 17 is formed with a seat for thevalve 19, and from this valve seat there leads another conduit 20 in adirection toward chamber 3,

terminating at a small chamand ultimatel d by a screw plug 22.

ber 21 entere the same chamber.

body by Carried by the screw plug 22, is a Bohr don tube 27 which may beflattened, as best indicated in Fig. 5, and at the free end of this tubethere is secured a clip 28, which may be separated from the tube 27,- sofar as any electric connection therewith is concerned by a layer 29 ofinsulation.

The clip 28 carries a conducting plate 30, which, as will hereinafterappear, is designed to operate as a bridging conductor.

Secured to the end of the body portion 1, v

remote from the chambers 2 and 3, is a plate or block 31 of insulation,made fast tothe carries "alsuitable number of. binding posts each actingas a clamp screw for an electrical terminal finger 34: or 35, as thecasev .flow of fluid into thispassa -.-5 5-under pressure will therefore actto liftthe piston 6 against the f the'spring'l. 1 After the piston 6 hasbeen raised slightly by the fluid. another and more] direct stream ofthe fluid will'flow through the passage 13 of the valve and the opening.14 of the cage under the piston and which;

'jwill aid to a pistonto res may be. e a

The fingers 34-35 are carried on opposite sides of the block 31,and arein the'path of the bridging plate or ;blockj30, in one extreme or otherof its travel under'theaction of the Bourdon tube 27.;- The two fingers34;-

may constitute-the terminals of a suitable electric circuit and thetwo'fingers 35 may constitute the termiua-lsof another electric circuit.

Let it be assumed, that the chamber 2 has within it ,a quantityof someliquid, preferably a mobile liquid, which'will not freeze under existingtemperatures, and let it be 1 further assumed that-the normalllevel ofthe .liq1id is below the pipe 5;" r

houldair under pressure he introduced];- I-into' the chamber .22,throughthe ipe,:' 5,' the :-jpressure thereof on the surface 0 theliquid within the chamberwill force thejiiquid through the conduit".111'which will unseat"the ;valve 12 andpermit the liquid tolflowthrough the'opening 1 P10f the cage'14, into the ,[passage 16..',,'l,hevalve 19 checks the ge and the fluid up into the chamber 13,and

tension of certain extent in causing the screw plug 24,

screws 32. The block or plate 31 p tendency to move 1 exerted,and thecircuit at the fingers 34 is now' flowj will there broken at the fingersment of pressure. in the chamber 2, and the end to the pressure in thecone" 3 n t at an additional permsvided through which liquidc pay rp fom passage 16 through chamber 3. The liquid under pressure passing tothe chamber 3, will find ready access thereto because the opening of thevalve 12 and the piston 6 will yield to pressure against the spring 7the degree of pressure necessary to move the piston peing regulated bythe tension of the spring ing plate 30 is in electrical contact with thefingers 35, and the electric circuit of which the-fingers 35 form theterminals is completed at this point. 'As soon as the Bourdon tube isstraightened bythe pressure, the bridging piece 30 is moved out ofcontact with the fingers 35 and ultimately makes a contact with thefingers 34, thus completing the circuit ofwhich the fingers 34 are theterminals, at said fingers 34,

As long as the pressure is maintained in the pipe 5, the contact iscontinued at fingers 34, but as soon as the pressure is relieved at thepipe 5, the-spring Twill cause the piston 6,'to move toward the lowerend turn passage '16 to the Bourdon tube because the-valve 19 preventsit, but the valve 19 will open to superior pressure on the Bourdon sidethereof when the piston 6 has come to rest, so that the pressure withinthe Bourdon tube may reduce as rapidly as the :liquid may pass throughtheleak passage -1113. This portor passage ,13 is very smal slightlylarger than a cambric needle, and

thecap or cage 14 is'provided merely to re- ,"tain the valve 12 in anoperative relation with" respect to its seat and may be of any suitableconstruction. On the reduction of pressure n the Bourdon tube, itsnatural toward the fingers 35 is broken, and the circuit at. fingers 35is ultimately again completed.

By this means the circuit may be quickly 35 after the establish circuitat the fingers 34 may be rapidly completed,-it being understood thatwhen fluid Epasses into chamber 2 it will be of sufficient pressure toquickly move the circuit conbeen reduced before the Bourdentroller.gHowei-'er a considerable time will elcpseafterthe pressure inthe Pipe 5 has tube will return bridge-3O and return to its normalposition, in view of the fact that the valve 12 is seated and the fluidmust pass through the needle passage 13 therein.

What is claimed, is

1. In combination, a pressure-responsive circuit controller, a conduitfor the supply of fluid under pressure thereto, branch passages leadingfrom the supply conduit to the circuit controller, a pressure-actuateddevice between said conduit and one of said branch passages and to beactuated by pressure from the conduit, means in said last-mentionedbranch passage for checking flow from the controller to the conduit butpermitting flow to the controller, and means in the other branch passagefor checking flow from the conduit to the controller but permitting flowfrom the controller back to the supply conduit.

2. In combination, a pressure-responsive circuit controller, a conduitfor the supply of fluid under pressure thereto, a supply passageextending from the conduit to the controller, means between said conduitand passage for controlling communication between the conduit and saidpassage, a return passage extending from the controller to the conduitand leading around the controlling means between said supply passage andconduit, means in said supply passage to prevent a reverse flow backthrough the passage to the conduit, and means in said return passage toprevent direct flow therethrough from the conduit to the controller.

3.-In combination, a pressure-responsive circuit controller, a conduitfor the supply of fluid under pressure, two passages for communicationbetween the conduit and the controller, a pressure-actuated devicecontrolling communication between the conduit and one of said passagesto be operated by fluid of. difi'erent pressures, two oppositely workingvalves, one in each passage, whereby fiuid under pressure from theconduit will hold one valve closed and will operate the pressureactuated device and hold the other valve open so as to cause the fluidunder pressure to flow to the circuit controller through one of saidpassages, and whereby upon insufficiency of fluid under 7 pressure inthe conduit the pressure-actuated device will cut off communicationbetween the conduit and one of said passages and the first of saidvalves will open whilethe second will close to cause return of the fluidfrom the controller to flow around pressure actuated device through theother of said passages to the conduit.- r

4; A pressure-actuated switch comprising.

a body member having a chamber forme therein, a pressure-responsivecircuit controller mounted upon the body, a supply conduit communicatingwith the chamber, said body having a passage therein connecting saidchamber and circuit controller, a pressure-actuated device normallycutting off fluid between the passage and chamber and determining thepressure at which fluid shall enter said passage, said body having asecond passage therein providing a return bypass around saidpressure-actuate'd device for the fluid from the controller to theconduit, means in said second passage to prevent direct flow from theconduit to the controller, and means in the first passage to preventback flow from the passage to the chamber.

5. In combination, a pressure responsive circuit controller, a conduitfor the supply of fluid. under pressure, a supply passage leadingfrom'said conduit to said controller, an exhaust passage leading fromsaid controller to said supply conduit, a resilient pressure actuateddevice for controlling said supply passage and operable by pressure insaid conduit,'an exhaust valve opening outwardly in said exhaustpassage, said passages opening into each other near the point ofcommunication with said conduit, Whereby the resilient pressure actuateddevice Will close said supply passage and tend to maintain pressure insaid exhaust passage to hold the exhaust valve closed when the pressureactuated device is not in normal position.

6. In combination, a pressure responsix e circuit controller, a conduitthrough which pressure .fluid may flow to and from said circuitcontroller, a chamber with which said conduit communicates at one end,an exhaust passage leading from said circuit controller to said end ofsaid chamber, a supply passage leading from a point intermediate theends of said chamber to said circuit controller, a piston valve slidablein said chamber and adapted to be movedby pressure in said conduit to aposition to open said supply passage, said piston valve normally tendingto close said supply passage and approach the conduit end of saidchamber, and an outwardly opening valve in said exhaust passage, wherebysaid piston valve will maintain pressure in said exhaust passage to holdsaid valve closed when the pis- 4 ton valve is approaching the end ofsaid chamber after a fall of pressure in said con-

